1. Field of the Invention
Embodiments of the present invention relate to an injection blow molding apparatus and method for forming molded articles.
2. Description of the Related Art
Injection blow molding (IBM) is a technique used for creating various containers such as plastic bottles for medication or other contents. The IBM process is performed with an IBM machine that first injection molds a resin into a plurality of parisons of desired shapes and then blow molds the parisons into the final molded articles.
An injection station of the IBM machine typically includes a split parison mold assembly that defines a plurality of cavities within which the parisons are formed. In the injection molding stage of the IBM process, the parison-forming surfaces of the split parison mold are heated to and/or cooled to different temperatures via a plurality of water lines foamed in the split parison mold near the parison-forming surfaces. The water lines may be supplied with water at different temperatures depending on the location of the water line relative to the neck or body of the parison being formed. Typically, a plurality of individual thermolators are required to control the temperature of water supplied to the various water lines in the parison mold and an operator is required to use a significant amount of discretion in making adjustments to the water temperature flowing through water lines at different locations along the body and/or neck of the parison during the injection blow molding process.
The operator discretion necessary to make certain parison mold designs function properly requires highly experienced IBM operators and can require significant trial and error in order to determine satisfactory operating parameters. Further, the complexity of manufacturing and operating split parison molds with multiple water lines formed therein can result in high capital costs, high operating costs, and high maintenance costs.
Thus, it would be desirable to have an injection molding system and/or process where IBM operator discretion is minimized, trial-and-error operation of the IBM operator is minimized, and mold tooling design, fabrication, replacement, and maintenance costs are minimized.